A stationery fastening device made of thin, soft metal, with a round head and a flat, split shank, which is spread after insertion in a hole in a stack of pages, in much the same way as a cotter pin or a split rivet.
Any similar stationery fastening device.
A small nail-like tack with a slightly rounded head that can be pressed into place with light pressure from the thumb; used for hanging light articles on a wall or noticeboard.
To fix or attach something with a thumbtack.